We propose to study the growth and changing population composition of American suburbs in the postwar period, and to focus particularly on the 1970-1980 decade. Our purpose is to describe the patterns of suburban growth in recent years, with a major emphasis on investigating differences in growth patterns between metropolitan areas. We interpret these trends within the general framework of the Burgess life-cycle model of urbanization, which posits regularities in the kinds of population characteristics which are likely to found together and hypothesizes typical phases of change over time in individual communities. To this model, we add an emphasis on the effects of the economic function of suburbs (the extent of growth in manufacturing and trade employment) and of the political context of growth (the resources, powers, and responsibilities of local government). We will focus on population characteristics corresponding to each of the three classical dimensions of social area differentiation: family income, occupation, and education levels (for socioeconomic status), population growth and age structure (for family status), and racial and ethnic composition (for ethnicity). For a sample of about 2,500 suburbs in 55 metropolitan regions, we will develop causal models of demographic change of individual communities and of patterns of change in suburban regions.